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NASA's Chandra finds black holes stirring up galaxies NASA NEWS RELEASE Posted: January 10, 2006 Black holes are creating havoc in unsuspected places, according to a new study of images of elliptical galaxies made by NASA's Chandra X-ray Observatory. The discovery of far-reaching explosive activity, due to giant central black holes in these old galaxies, was a surprise to astronomers.
"This is another example of how valuable it is to observe the universe at different wavelengths besides just the traditional optical wavelengths," said NASA's Chandra Program Scientist Wilt Sanders. "Without these X-ray and radio observations, we wouldn't know these apparently static galaxies in reality are still evolving due to the interaction with their central black holes." These results came from an analysis of 56 elliptical galaxies in the Chandra data archive by associate professor Thomas Statler and doctoral candidate Steven Diehl, both of the Physics and Astronomy department at the Ohio University, Athens, Ohio. Contrary to expectations, they found the distribution of the multimillion-degree gas in these galaxies differed markedly from that of the stars. "Most elliptical galaxies have traditionally been considered to be quiet places, like placid lakes," Statler said. "Our results show these galaxies are a lot stormier than we thought." Previous X-ray studies have shown elliptical galaxies contain multimillion degree gas whose mass is a few percent of the stars in it. Except for rare cases, violent activity in elliptical galaxies was thought to have stopped long ago. It was expected the hot gas would have settled into an equilibrium shape similar to, but rounder, than the stars. High angular resolution imaging observations by Chandra indicate otherwise. "We found the distribution of hot gas has no correlation with the optical shape," Diehl said. "Something is definitely making a mess there, and pumping energy equivalent to a supernova every century into the gas." Although supernovae are a possible energy source, a more probable cause was identified. The scientists detected a correlation between the shape of the hot gas clouds and the power produced at radio wavelengths by high-energy electrons. This power output can be traced back to the centers of the galaxies, where super-massive black holes are located. Repetitive explosive activity fueled by the in-fall of gas into central black holes is known to occur in giant elliptical galaxies located in galaxy clusters. Statler and Diehl's analysis indicates the same phenomena are also occurring in isolated elliptical galaxies. "These results are part of an emerging picture that shows the impact of super-massive black holes on their environment is far more pervasive than previously thought," Statler said. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Chandra researchers presented their data today during the 207th meeting of the American Astronomical Society in Washington. |
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This film looks at the highlights in NASA's history from its creation in the 1950s, through the glory days of the Mercury, Gemini and Apollo programs, birth of the space shuttle and the loss of Challenger, launch of Hubble and much more.
If at first you don't succeed, keep on trying. That is what the astronauts of space shuttle Endeavour's maiden voyage did in their difficult job of rescuing a wayward communications satellite. Spacewalkers were unable to retrieve the Intelsat 603 spacecraft, which had been stranded in a useless orbit, during multiple attempts using a special capture bar. So the crew changed course and staged the first-ever three-man spacewalk to grab the satellite by hand. The STS-49 astronauts describe the mission and narrate highlights in this post-flight presentation.
The mission for the crew of space shuttle Challenger's April 1984 flight was two-fold -- deploy the experiment-laden Long Duration Exposure Facility (LDEF) and then track down the crippled Solar Max spacecraft, capture it and perform repairs during spacewalks. Initial attempts by the astronauts to grab the craft while wearing the Manned Maneuvering Unit spacewalk backpacks failed, but the crew ultimately retrieved Solar Max and installed fresh equipment while it was anchored in the payload bay. The crew narrates this post-flight presentation of home movies and highlights from mission STS-41C.
The space shuttle program was grounded for 32 months in the painful wake of the 1986 Challenger accident. Americans finally returned to space in September 1988 when shuttle Discovery safely launched for its mission to deploy a NASA communications satellite. Enjoy this post-flight presentation narrated by the astronauts as they show movies and tell the story of the STS-26 mission.
Imagine a space shuttle mission in which the astronaut crew launched two commercial and one military communications spacecraft, then conducted a pair of incredible spacewalks to recover, fix and redeploy a satellite that malfunctioned just four months earlier. The rescue mission was a success, starting with an astronaut making a catch of the spinning satellite with just his gloved-hand. Enjoy this post-flight presentation narrated by the astronauts as they tell the story of shuttle Discovery's August 1985 mission known as STS-51I.
In our continuing look back at the classic days of the space shuttle program, today we show the STS-41D post-flight presentation by the mission's astronauts. The crew narrates this film of home movies and mission highlights from space shuttle Discovery's maiden voyage in August 1984. STS-41D deployed a remarkable three communications satellites -- a new record high -- from Discovery's payload bay, extended and tested a 100-foot solar array wing and even knocked free an icicle from the shuttle's side using the robot arm.